Floating-point benchmark comparison

[mohan ramamurthy]

Given below are the results of a study comparing the performance of various
computers (workstations as well as supercomputers) for six
floating-point-intensive Fortran codes.   These programs represent what you
might call a hierarchy of "typical" geophysical fluid dynamics models.
Identical codes were used on all machines, and no effort whatsoever was
made to explicitly optimize the codes on a particular machine - other than
the use of the highest available compiler optimization.   Some codes have a
large percentage of scalar computations (e.g., the QG model spends over 95
percent of its time in scalar segments), where as the others, like the PE model 
code and the Jacobian Operator program, contain several kernels that lend
themselves very well to vectorizing.  Additionally, the latter two codes
also contain numerous linked triad operations (e.g., D = A*B + C), which would 
explain the disproportionately high performance of those codes on computers with
vector and super-scalar architectures. Again, it should be reiterated that   
this benchmark suite is dominated by floating-point-intensive codes; therefore, 
it is NOT intended to reflect on other measures of CPU performance (like I/O, 
integer, etc.).





   			Relative Performance in MicroVAX Units
   			======================================


   	      Shallow  Spectral    QG    Multi-   Jacobian  Onelevel  Geom. Mean
              water    model      model  level    operator  channel
     	      model                      PE model           model.
==============================================================================

Cray-YMP	936.0	114.5	 120.4	1155.4	  2196.5   354.1     475.8

Cray-2		784.0	 79.7	  92.5   790.5	  1098.2   275.4     333.7

Cray-XMP	549.3	 77.7	  89.3	 442.4	   878.6   165.3     250.1

CYBER 205       126.8	 38.9	  42.8	 272.6	   399.4    65.2     107.0

Stardent GS2000 164.8	 27.5      9.5*  128.0	   366.1    43.5      66.7

Convex C220	109.9	 19.8	  20.8	 105.9	   244.1    45.9      61.4

IBM RS6000/320   48.5	 30.8	  38.0	  75.8	    81.4    42.7      49.6

Stardent GS1000 103.0	  7.0	   6.9	  67.3	   122.0    18.0      30.0

DECstation 5000  43.4	 17.3	  38.6	  41.6	    22.1    25.0      29.6

Apollo DN10000   53.2	  9.8	  41.4	  29.5	    23.2    33.0      28.0

Silicon Gr 4D/25 32.6    10.1*    29.3    25.7      22.9    15.8      21.1

DECstation 3100	 28.4	 10.0	  25.5	  24.7	    22.1    16.2      20.9

HP 9000/835	 16.7	  7.9	  16.3	  16.6	    18.3     9.7      13.6

Sparcstation 1	 12.6	  4.6	  10.3	  16.0	    11.6     8.7       9.9

MicroVAX II    	  1.0	  1.0	   1.0	   1.0 	     1.0     1.0       1.0

============================================================================
*Could not run at the highest optimization level.
Cray and Convex timings were obtained using just one processor.


================================================================================
Prof. Mohan K. Ramamurthy                  |Internet:mohan at uiatma.atmos.uiuc.edu
Department of Atmospheric Sciences         | DECnet: uiatmb::mohan
University of Illinois at Urbana-Champaign | ZAP (FAX):  (217) 244-4393
PONY EXPRESS : 105 S. Gregory Avenue       | Telephone:  (217) 333-8650
               Urbana, IL  61801           | ICBM: 40.08N  88.31W                           

			"Read my MIPS: No new VAXes"

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